geiger



Sept; 27,

true/away P. H. GEIGER RAILWAYTRAIN CONTROL APPARATUS Filed Oct. 15 1926 INVENTOR Patented Sept. 27, 1927.

1 [UNITED 'STTES rarer eerie 'PAUYL Ill-I. .GEIGER, or Wll'iKINSBURG, PENNSYLVANIA, ASSIGNOB TO THE UNION SWITCH,'& SIG AL COMPAN orsWIssVALE, PENNSYLVANIA, A CORPORATION or PENNSYLVANIA.

nAILwAY-TRAIN-ooN'rRon APPARATUS.-

Application filed October 13,; 1926. Serial No. 141,334.

trol apparatus, and'particularly to apparatus of the intermittent inductive type in- 'volving inductors locatedat intervals 1n the trackway and receivers on the trains.-

I will describe one form of-apparatus em-, bodying my invention, and will then point out the novel features thereof in'claims.

" The accompanying drawing is a diagramister respectively with the inductor legs 1,

2 and 3 the receivenmoves 'over the in- I ductor.

' The'inductor A is provided withwa winding C located between the legs 1 and-2, and

'a second winding 0 locatedbetween the legs 2'and 3. These windings areconnectedfto 'gether,- but may bothbe placed on short circuit by a-contact 9 of a relay T which may be controlled in any'desired manner.

, .Thezreceiver B is provided with a primary winding P whichis located between the legs 1" nd- 2 andi is included in a "primary cir- V cuit with a battery 4. Thejreceiver is also provided with a secondary winding S, which is located between the legs2 and 3, and is included in. a secondary circuit which passes from a battery 5, through the. winding of a 1 4e relay R, front contact6 ofrela-y R, and the secondary S to-the battery 5. -A second front contact 7 of relayR is included: in a circuit 8 which may be utilizedto controlany form of. governing apparatus on'the train, such, 4 for. example, as thetrain brakes or acab sig- The operation of the: apparatus is as'folenergized due tofcurrent from-battery 5.

Assuming that the train is movingin the di-" rection indicatedby the arrow 10, when the receiver B registers with the inductor A, as shown in the drawing, the magnetic flux due to current in the primary winding P will U My invention relates to railway train cond'eenergized.

flow in the path indicated by the solid arrows, thereby inducing a current in the winding C on inductor A. If contact 9 of relay T is open, the current produced in winding G will flow through winding C and the current in the latter winding will create a magnetic flux which will flow in the path indicatedby the arrows shown in dash lines; This flux will induce a current in the secondary winding S one half of each wave of which'will reduce or even reverse the current flowing through relay R from battery 5, and will thereby cause this relay to, become If, however, contact A of relay T is closed, substantially all of the current induced in winding C will flow through contact Q'Iinstead ofthrough winding C and, consequently, this current will have no effect on the secondary winding S and so will not cause relay R'to become de-v energized. i

I will now assume that the receiver B passes over a mass of iron in the trackway. When this iron is under legs 2 and 3*, there will be only a slight change in the magnetic flu); in that portion of the receiver core which 'includesthe secondaryflwinding S, since there is no considerable source-of mag netomotive force in this portion of the receiver core because of the resistance ofrelay R'which is included in circuit with battery;

5. There will, therefore, be only a slight change in the current flowing through secondary winding S, and, consequently, the, relay R will not be affected. When the iron is under the legs l and 2*, the flux through the portion of the receiver corewhich includes the primary winding P will increase, but thishasa negligible effect on the flux through the portion of the core including the secondary S,-and therefore will not affect therelay R. It will be seen, therefore, that no iron inthe trackway, othert'han the inductor A, will affect the train-carried rey R- Y o The magnetic structures of the inductor V and receiver may take several forms. For lowsrNormally' the train-carried relay R is 

